Upgrade any ability once in single-player mode.

Achievement Guide for Skilled

Achievement won on 15 Nov 14TA Score for this game: 3,571
Posted on 18 November 14 at 17:57

This solution has 18 positive votes and 1 negative vote. Please log in to vote.

Ability upgrades are the small icons next to the normal abilities. When you level up you get a skill point. Just buy the upgrade for any already unlock ability to unlock the achievement. You will start the game with a couple of abilities that can be upgraded. You can do this the first time you level up at the start of the game.